STAT3 and cancer: The IL-6/JAK/STAT3 pathway plays a key role in the growth and development of many human cancers (Johnson et al., 2018), and elevated IL-6 levels stimulate the overactivation of JAK/STAT3 signaling, which is usually related to poor patient outcomes (Ludwig et al., 1991; Kusaba et al., 2006; Chen et al., 2013).